The source is obviously ask.openstack.org. Question as it sounds originally :-

Can i create a tenant network and the packet will go out with the same fixed ip of the vm? Assuming the tenant network created is routable or identifiable in the physical network.

The answer is "YES". However , it is going to switch off Neutron L3 routing
and bring you back to simple flat networking with no DNAT/SNAT routing
involved.

Here is important to understand, that bridged neutron external networking
with SNAT disabled , won't provide you outbound internet connectivity ,
unless your VMs would have floating IPs assigned, however in case of using external network provider non bridged external networking will come into play. Via tap-interface (tap-e3b5d93-e6) attached to br-int neutron flow will be forwarded to Port (int-br-ex) , which makes a veth-pair with Port (phy-br-ex) . The last one belongs to bridge br-ex, the bridge which due to OVS configuration (presumably been tuned properly) will provide vice/versa Internet connectivity.

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Hence metadata access will be handled as in good old times via qdhcp
namespace generated by external flat network 192.169.142.0/24
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